The plague of Justinian or Justinianic plague was an epidemic of plague that afflicted the entire Mediterranean Basin, Europe, and the Near East, especially the Sasanian Empire and the Byzantine Empire. The plague is named for the Byzantine Emperor Justinian I who, according to his court historian Procopius, contracted the disease and recovered in 542, at the height of the epidemic which killed about a fifth of the population in the imperial capital Constantinople. The contagion arrived in Roman Egypt in 541, spread around the Mediterranean Sea until 544, and persisted in Northern Europe and the Arabian Peninsula until 549. By 543, the plague had spread to every corner of Justinian's empire.